ANALYST: Twitter Revealed IPO Date By Mistake: It's Nov. 15

Twitter will start selling stock to the public under the TWTR ticker symbol on Nov. 15, according to an analyst at PrivCo, who reverse-engineered the launch date from a revision in the company's S-1 disclosure to the SEC.

Typical employee stock "lock-up" periods, which prevent staff from selling their stock as soon as it goes public, are 90 days, PrivCo says. An earlier draft of the S-1 noted that the lock up ended Feb. 15, 2014, which puts the IPO date at Nov. 15 this year.